This invention relates to a device for producing a proof by creating a synthetic image from proofing films of various colors.
Conventionally, there have been proposed various proofreading processes which may provide an image approximately that of a final print without the need for printing a proof with an engraved printing plate and ink. For example, known transfer systems make use of photosensitive materials to carry out a proofing process. In these transfer systems, photosensitive layers containing selected color materials are transferred to a transfer ground paper one by one. Exposure and development are repeated for each color to form a synthetic image. Photosensitive adhesive layers are laminated on the ground paper for each color, and toner is applied after exposure.
However, these transfer systems require repetition of steps of exposure, development and coloring for each color, and also involve complex procedures so as to increase the cost of proofing.
To cope with the above-mentioned problems, Japanese Patent Application No. 57-176758 by the present applicant discloses sensitive materials which may provide original plates of each color separation film and accurate corresponding proofing films at the same time color separation of an original is conducted. According to the invention of the foregoing patent application, the above-mentioned problems in the prior art have been in a particular manner solved.
However, in method of the referenced patent application, at the same time the original plates for each color separation film are made, each image corresponding to that on the original plates is formed. Accordingly it is still required to accurately position the proofing films and the ground paper without slip-off of each color image which transferring each image from the proofing films to the ground paper.
In conventional transfer devices the ground paper and the color materials are laminated with each other, and are manually placed between a pair of heating rollers. In this process, images of the original plates for each color separation film are subjected to exposure after transfer of color materials. Accordingly there has been almost no problems in practical use as to relative positioning of the color materials and the ground paper, and each color material during transferring. However in the prior art laminater, many provisions have disadvantageously occurred such that (1) slip-off between the ground paper and the color materials, and each of color materials is created; (2) wrinkles of colored films and the ground paper are created; and (3) pores are created between the ground paper and the color materials, or each of the color materials.
A further type of conventional transfer device involves a system in which transfer to the ground paper is carried out after exposure and develoment of the proof-Oing film; in this system, it is stringently required to maintain positioning accuracy upon transferring because images are formed on the proofing films. To meet the requirement, a conventional transfer device includes a pin projecting from one of a pair of drums for rolling the proofreading film and another pin projecting from the other drum for rolling the ground paper. Accordingly, transferring is carried out by heat bonding the film and the paper between the drums.
However, in the foregoing transfer device, it is required to separately roll the ground paper and the proofing film, and, additionally, the rolling operation is troublesome. Further, since the ground paper and the proofing film are rolled on the drums in such a way that they are simply hooked by the pins on the drums, there is a risk of creating wrinkles in the proofing film upon transferring.
Although the above-mentioned problems in the prior art laminater have been solved in various ways and to various degrees, especially in the conventional transfer process, there is still the risk of slip-off between each transferred image, and accordingly the conventional transferring processes are not entirely satisfactory. Further, the creation of wrinkles and pores as mentioned above is a serious problem.
On the other hand, a still further proofing process involving an overlay system, is disclosed in Japanese Patent Laid-Open No. 58-113943, for example. In this overlay system, each film having images from original plates for each color separation film is laminated to the ground paper, or with each other where a ground paper is not used to form a synthetic image. However, in this system, there still exists the above-mentioned problems of slip-off between each film, and creation of wrinkles and pores that interfere with the fidelity of a proof.